| 摘要 |
PURPOSE:To obtain an LSI having excellent high frequency characteristic by forming a resistance region simultaneously upon formation of the base region of an I<2>L and introducing impurity to the resistor simultaneously upon formation of the base of the second transistor. CONSTITUTION:An N<+> type buried region 21 and a P type buried region 22 are formed on a P type Si substrate 20. Then, an epitaxial layer 23 having 0.5-2OMEGAcm of N type specific resistance is formed thereon. Thereafter, a P type isolation region 24 is formed, and the base 25 of an I<2>L and a resistor region 25' are simultaneously formed. Subsequently, a P<+> type resistance region 27 having lower sheet resistance than the region 25', base region 26, injector region 28 and base contact region 29 of an NPN transistor are simultaneously formed. Then, emitter region 30, collector contact region 31 and collector region 32 are simultaneously formed by N<+> type diffusion. Since the junction capacity of the resistor can be reduced, a low resistor having preferable high frequency characteristic can be obtained. |
